1. Field of Invention
The present invention relates to an audio processing circuit and its method, and more particularly to a POP noise suppressing circuit having a simple structure and an ability to suppress POP noise and a method thereof.
2. Description of Related Arts
POP noise is commonly produced in the processes of powering on and powering off an audio system.
In the audio system, a big capacitor usually works as a blocking capacitor when a power amplifier drives a speaker or an earphone. In the process of powering on, the voltage of the capacitor is supposed to increase to a common mode level; in the process of powering off, the voltage of the capacitor is supposed to decrease to zero, so that the speaker or the earphone is impacted in the processes of powering on and off, and the POP noise is produced and then brings discomfort to sensitive ears. Thus, it is necessary to provide a POP noise suppressing circuit and its method to effectively suppress the POP noise.